Improve C++ helpers

examples/example_host.cpp

@@ -7,8 +7,8 @@
 
 #include "example_host.h"
 
-#include <evmc/helpers.hpp>
 #include <evmc/helpers.h>
+#include <evmc/helpers.hpp>
 
 #include <map>
 

include/evmc/helpers.h

@@ -10,6 +10,8 @@
  * These are convenient for languages where invoking function pointers
  * is "ugly" or impossible (such as Go).
  *
+ * It also contains helpers (overloaded operators) for using EVMC types effectively in C++.
+ *
  * @defgroup helpers EVMC Helpers
  * @{
  */

include/evmc/helpers.hpp

@@ -4,11 +4,10 @@
  */
 
 /**
- * EVMC C++ helpers
+ * @file
+ * A collection of helpers (overloaded operators) for using EVMC types effectively in C++.
  *
- * A collection of helpers (overloaded operators) for using EVMC effectively in C++.
- *
- * @defgroup cpphelpers EVMC C++ helpers
+ * @addtogroup helpers
  * @{
  */
 #pragma once
@@ -19,31 +18,31 @@
 #include <functional>
 
 /// The comparator for std::map<evmc_address, ...>.
-bool operator<(const evmc_address& a, const evmc_address& b)
+inline bool operator<(const evmc_address& a, const evmc_address& b)
 {
-    return std::memcmp(a.bytes, b.bytes, sizeof(a)) < 0;
+    return std::memcmp(a.bytes, b.bytes, sizeof(a.bytes)) < 0;
 }
 
 /// The comparator for std::map<evmc_bytes32, ...>.
-bool operator<(const evmc_bytes32& a, const evmc_bytes32& b)
+inline bool operator<(const evmc_bytes32& a, const evmc_bytes32& b)
 {
-    return std::memcmp(a.bytes, b.bytes, sizeof(a)) < 0;
+    return std::memcmp(a.bytes, b.bytes, sizeof(a.bytes)) < 0;
 }
 
 /// The comparator for equality.
-bool operator==(const evmc_address& a, const evmc_address& b)
+inline bool operator==(const evmc_address& a, const evmc_address& b)
 {
-    return std::memcmp(a.bytes, b.bytes, sizeof(a)) == 0;
+    return std::memcmp(a.bytes, b.bytes, sizeof(a.bytes)) == 0;
 }
 
 /// The comparator for equality.
-bool operator==(const evmc_bytes32& a, const evmc_bytes32& b)
+inline bool operator==(const evmc_bytes32& a, const evmc_bytes32& b)
 {
-    return std::memcmp(a.bytes, b.bytes, sizeof(a)) == 0;
+    return std::memcmp(a.bytes, b.bytes, sizeof(a.bytes)) == 0;
 }
 
 /// FNV1a hash function with 64-bit result.
-static inline uint64_t fnv1a_64(const uint8_t* ptr, size_t len)
+inline uint64_t fnv1a_64(const uint8_t* ptr, size_t len)
 {
     constexpr uint64_t prime = 1099511628211ULL;
     constexpr uint64_t offset_basis = 14695981039346656037ULL;
@@ -57,20 +56,27 @@ static inline uint64_t fnv1a_64(const uint8_t* ptr, size_t len)
     return ret;
 }
 
-static_assert(sizeof(size_t) == sizeof(uint64_t), "size_t is not 64-bit wide");
-
 namespace std
 {
-/// Hash operator template needed for std::ordered_set and others using hashes.
+/// Hash operator template specialization for evmc_address needed for unordered containers.
+template <>
+struct hash<evmc_address>
+{
+    /// Hash operator using FNV1a.
+    std::enable_if<sizeof(size_t) == 8, std::size_t>::type operator()(const evmc_address& s) const
+        noexcept
+    {
+        return fnv1a_64(s.bytes, sizeof(s.bytes));
+    }
+};
+
+/// Hash operator template needed for std::unordered_set and others using hashes.
 template <>
 struct hash<evmc_bytes32>
 {
-    /// The argument type.
-    typedef evmc_bytes32 argument_type;
-    /// The result type.
-    typedef std::size_t result_type;
     /// Hash operator using FNV1a.
-    result_type operator()(argument_type const& s) const noexcept
+    std::enable_if<sizeof(size_t) == 8, std::size_t>::type operator()(const evmc_bytes32& s) const
+        noexcept
     {
         return fnv1a_64(s.bytes, sizeof(s.bytes));
     }

test/unittests/CMakeLists.txt

@@ -39,6 +39,7 @@ add_custom_command(
 
 add_executable(
     evmc-test
+    test_helpers.cpp
     test_instructions.cpp
     test_loader.cpp
 )

test/unittests/test_helpers.cpp

@@ -0,0 +1,29 @@
+// EVMC: Ethereum Client-VM Connector API.
+// Copyright 2018 The EVMC Authors.
+// Licensed under the Apache License, Version 2.0. See the LICENSE file.
+
+#include <evmc/helpers.hpp>
+
+#include <gtest/gtest.h>
+
+#include <map>
+#include <unordered_map>
+
+TEST(helpers, maps)
+{
+    std::map<evmc_address, bool> addresses;
+    addresses[{}] = true;
+    ASSERT_EQ(addresses.size(), 1);
+
+    std::unordered_map<evmc_address, bool> unordered_addresses;
+    unordered_addresses.emplace(*addresses.begin());
+    EXPECT_EQ(unordered_addresses.size(), 1);
+
+    std::map<evmc_bytes32, bool> storage;
+    storage[{}] = true;
+    ASSERT_EQ(storage.size(), 1);
+
+    std::unordered_map<evmc_bytes32, bool> unordered_storage;
+    unordered_storage.emplace(*storage.begin());
+    EXPECT_EQ(unordered_storage.size(), 1);
+}